Photos: World’s Largest Turret Module Sets Sail for South Korea

The largest module of the mooring turret for the largest floating structure ever constructed has set sail from Dubai for the Samsung Heavy Industries shipyard in Geoje, South Korea.

The piece of turret is part of the mooring system for Shell’s Prelude Floating Liquefied Natural Gas (FLNG) facility, a massive, 600,000 ton facility that will allow Shell to produce natural gas at sea, cool it onboard into LNG, and pump it directly into ships that will transport it around the world.

The turret mooring system, designed by SBM Offshore and constructed at Dubai DryDocks World, will ensure that the Prelude FLNG can operate safely while permanently moored over the Prelude gas field off the coast of Australia for 25 years, even during the most extreme weather events.

To accomplish this, the turret system features a swivel design that uses a bearing arrangement and enables the facility to freely ‘weather vane’, or rotate according to the prevailing wind, waves or current, while the turret moorings remain fixed to the sea floor.

At almost 100 meters tall and weighing 4,300 tons, the turret module will run through the front of the Prelude FLNG facility, connecting mooring lines to 62.5 meter long and 5.5 meter diameter anchor piles secured to the seabed. The mooring system includes four groups of four mooring lines, sixteen in total, that will secure the facility to the anchor points about 250 meters below the surface of the sea. The mooring chain links will also be among the largest in the world at about one meter in length.

In addition to the mooring system, the subsea connections that extract and control the flow of gas from the reservoir below also connect via the turret.

“Prelude FLNG combines our many years of experience in shipping and in managing complex LNG and offshore projects. It’s great to see our innovative designs and technologies become a reality as we reach significant project milestones like this,” Matthias Bichsel, Projects & Technology Director at Shell said.

“Designed in Monaco, built in Dubai, shipped to South Korea and for use off Australia, the turret is an example of the truly global nature of this project,” added Bichsel.

Once complete, the Prelude FLNG will operate in a remote basin around 200 kilometers off Australia’s north-west coast for 25 years, produceing 3.6 million tonnes per annum (mtpa) of LNG, 1.3 mtpa of condensate and 0.4 mtpa of LPG.